This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are using a visual stimulus paradigm that produces well-characterized localized neural inhibition in primary visual cortex to test whether, on a fine spatial scale, the positive BOLD response is more closely related to the neural output or the local neural inhibition. In the past year we have published one paper demonstrating that the V1 BOLD response correlates better with the magnitude of the local neural inhibition than with the local neural output;a second manuscript is in preparation.